Tailored Design‐of‐Experiments Approach for Device Performance Prediction and Optimization of Flash‐Evaporated Organic–Inorganic Halide Perovskite‐Based Photodetectors

Abstract

Single‐source flash evaporation method has recently gained attention for its potential as a rapid and solvent‐free deposition method for producing organic–inorganic halide perovskite (OHP) films in large‐scale. However, due to a complex nature of the different experimental parameters involved in the deposition process, it is not straightforward to obtain the optimal condition for producing high‐quality OHP films. In this study, this problem is tackled by employing the design‐of‐experiment (DoE) process, which is an efficient statistical analysis for finding an optimized condition with a minimized number of experiments. The DoE process is used for optimizing the responsivity of the OHP photodetector devices against the input variables used in the deposition that yielded an enhanced responsivity of 112.2 mA W−1, which is up to an order of magnitude higher than that of the unoptimized devices. The experimental results using the DoE method provide not only the conditions required for enhancing the device performance but also the guidelines for improving the overall film quality through exploring the variable space of the flash evaporation technique.

Photo‐Responsive Molecular Junctions Activated by Perovskite/Graphene Heterostructure Electrode

“…[42] The perovskite film was then deposited through the single-source evaporation method, as we previously reported. [43,44] The detailed fabrication process is described in the Experimental Section and depicted in Figure S1, Supporting Information. Figure 1b shows images sequentially magnified from a whole substrate piece to a molecular junction from left to right in order: entire and enlarged optical microscope images of fabricated molecular junction devices on substrates, an atomic force microscope (AFM) image of a hole with a radius of 2 µm, and a cross-sectional transmission electron microscope (TEM) image of a molecular junction.…”

“…[50] Therefore, we used the single-source evaporation method to deposit a high-quality film of OHP with high uniformity and without pinholes, regardless of the surface energy on the substrate material. [43,44] First, MAPbI 3 powder, which can be used as the flash-evaporation source, was synthesized with high purity and characterized by powder X-ray diffraction (XRD) spectra (Figure S2, Supporting Information). Field-emission scanning electron microscope (FE-SEM) images, shown in Figure 1f, confirmed that a pinhole-free and uniform MAPbI3 film with a film thickness of ≈200 nm was formed by the flash evaporation (bottom image of Figure 1f).…”

“…Synthesis of Perovskite Powder: The authors synthesized MAPbI 3 single crystal powders as reported previously. [43,44] PbO powders, hydriodic acid (HI, 57 wt% in H 2 O), and hydrophosphorous acid (H 3 PO 2 , 50 wt% in H 2 O) were purchased from Sigma-Aldrich. Methylammonium iodide (MAI) was purchased from Greatcell Solar Materials Ltd.…”

“…They used the single source flash evaporation method to deposit perovskite films onto the molecular devices. [43,44] The prepared MAPbI 3 and MAI powders (366 mg of MAPbI 3 and 99.96 mg of MAI) were loaded onto a tungsten boat in a vacuum chamber. The substrates were placed with shadow masks at the height of 30 cm away from the source material.…”

Machine Learning-Enhanced High-Throughput Fabrication and Optimization of Quasi-2D Ruddlesden-Popper Perovskite Solar Cells

“…[49][50] Another factor that slows down the progress is the use of one-step-at-atime classical systematic experimentation procedure that has a substantial disadvantage of not considering interactions between input parameters. 51 Remarkably, RPP perovskite precursor solutions at molar concentrations (M) below ~0.7 M crystalize into uniform and highly crystalline films when deposited via a simple drop-casting technique. [52][53] An interesting method was employed in 2021 by Zuo et al, 54 who used a simple drop casting methodology on mildly preheated substrates for perovskite fabrication.…”